If I recall as was shown with one of their previous works the general drawing is done by the AI and then heavily cleaned up on details, such as the joints, hair, etc. Though I imagine the difference in her arm widths is an AI hiccup. The arm on the left is practically a twig compared to the arm on the right.
He's not so much redrawing as img2imging it, both the 'prototype' as shown in comment #2389521 (link now expired though) and the final image were clearly artefacted in different areas. The entire picture changed, including stuff that didn't require correcting at all like the BG, which indicates either an img2img of the whole thing or generation from the same seed on different settings. NAI v3 is too good at high tag count details like doll joints and doesn't really need manual refining in this regard. This one has a lot of issues as well, like the jacket breaking in half behind her back, hair strands appearing from nowhere under her left arm, and hair blending with mattress.